The common bed bug, Cimex lectularius, possesses a cholinesterase expressed exclusively in the salivary gland (ClSChE). In this paper, we investigated the molecular structure, tissue distribution patterns, and biochemical properties of ClSChE and showed that ClSChE exists as a soluble monomeric form or a soluble dimeric form connected by a disulfide bridge. Immunohistochemical analysis confirmed that ClSChE was expressed in the epithelial cells of both the salivary gland and the duct. In addition, the secretion of monomeric ClSChE through the proboscis during feeding was detected by western blotting using a ClSChE-specific antibody. To predict the role of ClSChE injected into the tissue of an animal host, we analyzed the extent of sequestration and hydrolysis of acetylcholine (ACh)/choline (Ch) by ClSChE by ultra-performance liquid chromatography-tandem mass spectrometry. Kinetic analysis revealed that ClSChE possesses extremely low Km (high affinity to ACh) and Vmax values. These findings suggest that ClSChE functions as a sequestering enzyme specific to ACh (not to Ch) by having a very strong affinity to ACh but an extremely long turnover time.

• Ju Hyeon Kim(Department of Veterinary and Animal Science, University of Massachusetts)
• Chae Eun Hwang(Department of Animal Management and Research, National Institute of Ecology)
• Kyungjae Andrew Yoon(Department of Agricultural Biology, Seoul National University)
• Keon Mook Seong(Department of Entomology, Michigan State University)
• Jonghwa Lee(Department of Agricultural Biology, Seoul National University)
• Jeong Han Kim(Department of Agricultural Biology, Seoul National University, Research Institute of Agriculture and Life science, Seoul National University)
• Si Hyeock Lee(Department of Agricultural Biology, Seoul National University, Research Institute of Agriculture and Life science, Seoul National University)